Obama's announcement smacks of political calculation -- it's hard to believe that he hasn't privately supported gay marriage for years, and his "evolving" perspective had to do more with polling numbers versus a struggle of conscience.

Meanwhile, one can argue that North Carolina voters are putting themselves on the wrong side of history. It seems a safe bet that a generation from now, those opposing gay marriage are going to look a lot like those who defended racial segregation.

The fact is, it's hard to fashion a convincing case that gay marriage undermines American values or hurts society. If you accept the idea that homosexuality is a biological trait versus a choice, than denying gays and lesbians the right to marry seems arbitrary, even mean-spirited. The benefits to those couples is obvious; the harm to others is, frankly, elusive.

That said, I'm among those deeply concerned about the state of marriage in America. It's an institution in crisis, but in my opinion, it has nothing to do with gays wanting to marry. Rather, it's the growing reluctance of heterosexuals to commit, even when children are involved.

I've made this point before, but it bears repeating: One of the most worrisome trends in U.S. society is the increasing number of babies born outside of wedlock.

According to a report last month, 47 percent of babies born in Kalamazoo County in 2010 were to unwed mothers — up from 35 percent in 2000. Statewide, the number is 41 percent.

The conventional wisdom, at least in some circles, is that out-of-wedlock births are concentrated among welfare mothers who start having babies as teen-agers and flit from boyfriend to boyfriend.

"The mothers don't need no stinkin' REAL daddy. In fact, most don't know who the sperm donor is," one online commenter wrote last month in response to the mlive.com story on the last numbers.

"Have a baby, get a check," wrote another commenter.

That doesn't quite square with the reality. The teen birth rate has plummeted over the past decade. Because of welfare reform, the percentage of Americans receiving cash welfare benefits was actually slightly lower in 2010 than it was in 1960, according to federal data.

In short, unwed motherhood isn't a trend confined to people living on the margins. It's become part of mainstream America.

The explosive growth in unmarried mothers has largely occurred among women in their 20s, many of them white and middle class, who get pregnant but decide they "aren't ready" for marriage. Off the top of my head, I could name several couples of my acquaintance who fit that description.

On one hand, I suppose it's admirable that people respect the institution of marriage enough to understand that it shouldn't happen on a lark, that one needs to see it as a lifelong commitment.

On the other hand, there's plenty of evidence that this is a terrible, horrible, no good, very bad trend for children, not to mention society in general.

Research is clear that children born outside of marriage in the United
States are much more likely to live in poverty, more likely to struggle
in school, more likely to have emotional and behavior problems.

The
data shows that a third of Kalamazoo County children in
single-parent households, and those families are six times more likely
to live below the poverty line. In Kalamazoo County, 7 percent of
married-couple families with children live in poverty, compared to 41
percent of households headed by single moms.

While it's
true that most unmarried American women who give birth are in a
committed relationship, those relationships tend to fall apart fairly quickly. Only 35 percent of unmarried couples who have a baby are still together by the time the child turns 5, and only half of the fathers saw their child even once a month, the Brookings report says.

Marriage may be just a "piece of paper," but it's a piece of paper that matters -- especially to children.

From that vantage point, it's ironic that one of the critics of Obama's new stance on gay marriage is Bristol Palin, who argues that children are much better off with both a mother and a father.

The irony is twofold: One, Palin raising her own son as a single mother and, second, studies show children raised by gay couples aren't that different from their peers in more conventional two-parent families. Just based on the research, it's much better to grow up in a household headed by a gay couple versus a situation like Bristol Palin.

There's also a larger irony that so much time and energy is being expended on debating whether gay marriage undermines American family life when the real, far more pressing problem is elsewhere.